Luận án tiến sĩ về sự giải phóng nitrogen từ hạt urê phủ: Mô hình hóa và mô phỏng

Luận án tiến sĩ kỹ thuật nghiên cứu kỹ thuật hóa học study the release of nitrogen from coated urea granule modelling and simulation, phân tích chuyên sâu, xây dựng mô hình lý

• Tác giả: Trinh Hoai Thanh
• Người hướng dẫn: Assoc. Ku Zilati Ku Shaari
• Trường học: Universiti Teknologi Petronas
• Chuyên ngành: Chemical Engineering
• Đề tài: Nghiên Cứu Sự Giải Phóng Nitrogen Từ Hạt Urê Phủ: Mô Hình Hóa Và Mô Phỏng
• Loại tài liệu: thesis
• Năm xuất bản: 2016
• Địa điểm: Bandar Seri Iskandar

Tóm tắt

I. Giới thiệu

Nghiên cứu về sự giải phóng nitrogen từ hạt urê phủ là một lĩnh vực quan trọng trong ngành nông nghiệp hiện đại, nhằm nâng cao hiệu quả sử dụng phân bón và giảm thiểu tác động tiêu cực đến môi trường. Phân bón urê được biết đến là một nguồn cung cấp nitrogen chính cho cây trồng, tuy nhiên, việc sử dụng không hiệu quả có thể dẫn đến hiện tượng thất thoát nitrogen thông qua bay hơi và rửa trôi. Do đó, việc phát triển các loại phân bón urê có khả năng giải phóng dinh dưỡng một cách kiểm soát là rất cần thiết. Mô hình hóa và mô phỏng quá trình này không chỉ giúp hiểu rõ hơn về cơ chế giải phóng mà còn hỗ trợ trong việc thiết kế các loại phân bón thông minh. Các nghiên cứu trước đây đã chỉ ra rằng việc áp dụng các mô hình toán học có thể dự đoán chính xác hơn về sự giải phóng nitrogen từ các loại phân bón khác nhau.

II. Phương pháp nghiên cứu

Nghiên cứu này áp dụng các phương pháp mô hình hóa và mô phỏng để phân tích quá trình giải phóng nitrogen từ hạt urê phủ. Các mô hình được phát triển bao gồm mô hình thẩm thấu đa chiều và mô hình phân rã, cho phép mô phỏng chính xác các giai đoạn khác nhau của quá trình giải phóng. Cụ thể, mô hình đầu tiên tập trung vào giai đoạn thẩm thấu nước vào hạt urê, trong khi mô hình thứ hai mô phỏng sự giải phóng nitrogen trong các điều kiện khác nhau của môi trường như nước và đất. Kết quả của mô phỏng cho thấy rằng sự phân bố độ dày của lớp phủ có ảnh hưởng lớn đến tốc độ giải phóng dinh dưỡng từ phân bón urê. Những phát hiện này không chỉ giúp cải thiện hiệu suất của phân bón mà còn đóng góp vào việc quản lý dinh dưỡng cây trồng hiệu quả hơn.

III. Kết quả và thảo luận

Kết quả từ nghiên cứu cho thấy mô hình mô phỏng đã dự đoán chính xác sự giải phóng nitrogen từ hạt urê phủ trong môi trường nước và đất. Các thông số như độ dày lớp phủ và loại đất ảnh hưởng mạnh mẽ đến quá trình này. Cụ thể, khi lớp phủ dày hơn, tốc độ giải phóng dinh dưỡng sẽ chậm hơn, điều này có thể hữu ích trong việc điều chỉnh lượng phân bón phù hợp với nhu cầu dinh dưỡng của cây trồng. Ngoài ra, nghiên cứu cũng chỉ ra rằng việc tối ưu hóa các thông số thiết kế của phân bón urê có thể dẫn đến hiệu quả sử dụng nitrogen cao hơn, từ đó góp phần vào việc giảm thiểu ô nhiễm môi trường do phân bón. Như vậy, nghiên cứu không chỉ có giá trị lý thuyết mà còn có ứng dụng thực tiễn cao trong ngành nông nghiệp hiện đại.

IV. Kết luận

Nghiên cứu này đã cung cấp cái nhìn sâu sắc về quá trình giải phóng nitrogen từ hạt urê phủ thông qua việc áp dụng các phương pháp mô hình hóa và mô phỏng. Những phát hiện từ nghiên cứu không chỉ giúp cải thiện hiệu quả sử dụng phân bón mà còn góp phần vào việc bảo vệ môi trường. Việc phát triển các loại phân bón thông minh với khả năng giải phóng dinh dưỡng theo nhu cầu của cây trồng là một bước tiến quan trọng trong ngành nông nghiệp bền vững. Các khuyến nghị cho nghiên cứu trong tương lai bao gồm việc mở rộng nghiên cứu sang các loại phân bón khác và thử nghiệm trong điều kiện thực tế để xác nhận tính khả thi của các mô hình đã phát triển.

Trích đoạn nội dung tài liệu

STUDY THE RELEASE OF NITROGEN FROM COATED UREA GRANULE: MODELLING AND SIMULATION TRINH HOAI THANH DOCTOR OF PHILOSOPHY CHEMICAL ENGINEERING UNIVERSITI TEKNOLOGI PETRONAS AUGUST 2016 STATUS OF THESIS Study the release of nitrogen from coated urea granule: Modelling and Title of thesis simulation TRINH HOAI THANH I _________________________________________________________________________ hereby allow my thesis to be placed at the Information Resource Center (IRC) of Universiti Teknologi PETRONAS (UTP) with the following conditions: 1. The thesis becomes the property of UTP 2. The IRC of UTP may make copies of the thesis for academic purposes only. This thesis is classified as Confidential Ö Non-confidential If this thesis is confidential, please state the reason: ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ The contents of the thesis will remain confidential for ___________ years.

Remarks on disclosure: ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ Endorsed by ________________________________ __________________________ Signature of Author Signature of Supervisor 94 A1 Hung Permanent address:________________ Name of Supervisor Vuong, ward 9, district 5, HCMC, ________________________________ Assoc. Ku Zilati Ku Shaari __________________________ Vietnam ________________________________ ________________________________ Date : _____________________ Date : __________________ UNIVERSITI TEKNOLOGI PETRONAS STUDY THE RELEASE OF NITROGEN FROM COATED UREA GRANULE: MODELLING AND SIMULATION by TRINH HOAI THANH The undersigned certify that they have read, and recommend to the Postgraduate Studies Programme for acceptance this thesis for the fulfillment of the requirements for the degree stated. Signature: ______________________________________ Main Supervisor: Assoc. Ku Zilati Ku Shaari ______________________________________ Signature: ______________________________________ Co-Supervisor: "[Click Here to Enter Name]" ______________________________________ Signature: ______________________________________ Head of Department: Assoc.

Suriati Binti Sufian ______________________________________ Date: ______________________________________ STUDY THE RELEASE OF NITROGEN FROM COATED UREA GRANULE: MODELLING AND SIMULATION by TRINH HOAI THANH A Thesis Submitted to the Postgraduate Studies Programme as a Requirement for the Degree of DOCTOR OF PHILOSOPHY CHEMICAL ENGINEERING UNIVERSITI TEKNOLOGI PETRONAS BANDAR SERI ISKANDAR, PERAK AUGUST 2016 DECLARATION OF THESIS Study the release of nitrogen from coated urea granule: Modelling and Title of thesis simulation TRINH HOAI THANH I _________________________________________________________________________ hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UTP or other institutions. Witnessed by ________________________________ __________________________ Signature of Author Signature of Supervisor 94 A1 Hung Permanent address:________________ Name of Supervisor Vuong, ward 9, district 5, HCMC, ________________________________ Assoc. Ku Zilati Ku Shaari __________________________ ________________________________ Vietnam ________________________________ 09-08-2016 Date : _____________________ 09-08-2016 Date : __________________ DEDICATION To my parent, Hoai Nam and Ha Anh, and my family for their support and patience during my research.

To my children for their understanding and all my love with them. To my supervisor who always be the inspiration for this thesis. v ACKNOWLEDGEMENTS I would like to express my deepest gratitude and appreciation to my supervisor, Dr. Ku Zilati Ku Shaari, for her excellent and constant guidance, patience, generous support, and valuable advice.

She introduces me to the world of qualitative research and shows me how to become a good researcher. Moreover, I would like to offer my most profound gratitude to OneBAJA, Centre for Biofuel and Biochemical Research, and Universiti Teknologi PETRONAS, Malaysia for providing a congenial work environment and state-of-the-art research facilities. The research grant extended to us by the Ministry of Education, Malaysia (MOE) (LRGS Fasa 1/2011) for ongoing research projects and the technical support from National Institute of Forensic Medicine, Vietnam is also highly acknowledged. I would like to thanks to my parent who always encourage and supporting me during my research, and also Ms.

Dao Nhat Quyen, the mother of my children, for her constant supporting to nurture and educate my children so that I can keep working on the research. In addition, the thank also goes to Ms. Tran Thi To Nga, my current wife, for being by my side through joys and pains all the time. The writing suggestions shared by Dr.

Noridah Osman, Mr. Babar Azeem, Universiti Teknologi PETRONAS, Malaysia, is highly appreciated. vi ABSTRACT Urea, when applied to crops is vulnerable to losses from volatilization and leaching. Controlled-release fertilizer (CRF) enhances nitrogen use efficiency by plants which not only increases the crop yields but also contributes towards environmental pollution control in terms of the alleviation of hazardous gaseous emissions and water eutrophication.

This study thoroughly investigates the release of nitrogen from CRF both in modeling and experimental aspects. The experiments are conducted to provide useful information for the model and validation process. Modeling and simulation section includes several models for each stage of the release including lag period, constant release, and decay release stages. Initially, a model for water penetration into CRF that related to the lag period was proposed and developed.

It is successfully simulated and experimentally validated. Second, a multi diffusion model was developed and simulated nitrogen release from coated urea particles for both the constant and decay release stages of urea. This model was developed for multilayer included the coating and water zone, and it also integrated a finite-element method (FEM) that employed 2D geometry to enhance the accuracy of by introducing urea diffusivity in water domain as a function of urea concentration. Simulation results agreed with preliminary experimental data to a standard error of estimate (SEE) that ranged from 0.0567, indicating the model successfully simulated and predicted nitrogen release from hours to days and from small to large particles.

A more thorough investigation was then conducted for which the model not only predicted nitrogen release from coated urea but also described the internal release mechanism of urea from the core to urea-coated interface and into the aqueous environment. Afterward, the model was modified and developed as a “porous” model to predict and simulate the release of nitrogen from either soils or water. Imperfection of coating thickness also is taken into account in the latest model. Finally, an approach has been proposed to predict/estimate the effective diffusivity of a coating vii material and to design geometric parameters for CRFs of which the release can match the nutrient uptake needs for a specific plant (i., Sj rice variety planting in Selangor).

viii ABSTRAK Menggunakan urea untuk tanaman akan menyebabkan kerugian akibat daripada pengewapan dan larut lesap. Kawalan pelepasan urea (CRF) akan meningkatkan kecekapan penggunaan nitrogen oleh tumbuh-tumbuhan yang bukan sahaja meningkatkan hasil tanaman tetapi juga menyumbang kepada kawalan pencemaran alam sekitar dari segi usaha mengurangkan pelepasan gas berbahaya dan eutrofikasi air. Kajian ini dengan teliti menyiasat pelepasan nitrogen dari CRF dalam kedua-dua aspek iaitu model dan eksperimen. Eksperimen dijalankan untuk menyediakan maklumat yang berguna untuk model dan pengesahan proses.

Bahagian pemodelan dan simulasi meliputi beberapa model untuk setiap peringkat pelepasan termasuk masa senggang, pelepasan berterusan dan peringkat penyusutan pelepasan. Pada mulanya , model untuk penembusan air ke dalam CRF yang berkaitan dengan masa senggang telah dicadangkan dan dibangunkan. Ia turut berjaya disimulasikan dan disahkan oleh eksperimen. Kedua, model pelbagai penyebaran telah dibangunkan dan simulasikan pelepasan nitrogen dari butir urea bersalut untuk kedua-dua iaitu peringkat pelepasan berterusan dan penyusuatan urea.

Model ini telah dibangunkan untuk berbilang lapisan termasuk zon salutan dan air, dan mengintegrasikan Kaedah Unsur Terhingga (FEM) dengan geometri 2D untuk meningkatkan ketepatan simulasi dengan memperkenalkan kemeresapan urea dalam domain air sebagai fungsi kepekatannya. Hasil keputusan simulasi selaras dengan data eksperimen awal dengan ralat piawai anggaran ( SEE ) antara 0.0567 dan ianya menunjukkan model telah berjaya disimulasikan dan menjangkakan pelepasan nitrogen samada jam atau hari dan samada kecil atau butir besar. Siasatan lebih menyeluruh kemudiannya dijalankan yang mana model bukan sahaja dapat menjangkakan pelepasan nitrogen dari urea bersalut tetapi juga menerangkan mekanisme pelepasan dalaman urea dari teras kepada antara muka urea bersalut dan ke dalam persikitaran berair. Selepas itu, model diubahsuai dan dibangunkan sebagai model " berliang " untuk menjangkakan ix dan mensimulasikan pelepasan nitrogen sama ada tanah atau air.

Ketidaksempurnaan ketebalan lapisan juga diambil kira dalam model terkini. Akhir sekali, pendekatan telah dicadangkan untuk menjangkakan/menganggarkan kemeresapan berkesan bahan salutan dan untuk mereka bentuk parameter geometri untuk CRFs yang pembebasannya dapat menandingi keperluan pengambilan nutrien untuk tumbuhan tertentu (iaitu , jenis beras Sj yang ditanam di Selangor). x In compliance with the terms of the Copyright Act 1987 and the IP Policy of the university, the copyright of this thesis has been reassigned by the author to the legal entity of the university, Institute of Technology PETRONAS Sdn Bhd. Due acknowledgement shall always be made of the use of any material contained in, or derived from, this thesis.

© Trinh Hoai Thanh, 2016 Institute of Technology PETRONAS Sdn Bhd All rights reserved. xi TABLE OF CONTENT ABSTRACT. ix LIST OF FIGURES. xvi LIST OF TABLES.

xxv CHAPTER 1 INTRODUCTION .1 Background of Study .4 Scope of Research. 11 CHAPTER 2 LITERATURE REVIEW .2 Fertilizers and Their Role on Plant Growth.3 Adverse Impacts of Fertilizers on the Environment.4 Controlled-Release Fertilizers and Slow-Release Fertilizers .1 Classification of CRFs .2 Mechanism of Controlled Release .3 Advantages and Disadvantages of CRF/SRFs .5 Coating Materials for CRF Production.1 CRF from Sulfur Based Coating Materials.2 CRFs Using Polymer-Based Coating Materials .3 CRF from Superabsorbent/Water Retention Coating Materials .4 CRF from Bio-composite-Based Coating Materials .5 Commercially Available Controlled-Release Coated Fertilizer .6 Modeling and Computational Fluid Dynamics .7 Role of Modeling in the Study of the Release of Nitrogen .1 Nitrogen Release Behavior Based on Regression and Kinetic Models .2 Nitrogen Release Behavior Based on the Mechanistic Model .3 Nitrogen Release Behavior in Soil. 45 CHAPTER 3 RESEARCH METHODOLOGY .2 Overall Research Project’s Methodology .1 Finite Element Method (FEM) .2 Time-dependent Solvers.4 Water Penetration Model in the Coating Layer .1 Theory of Fluids Transport in Porous Medium .3 Model Development for Water Penetrates into the Coating .4 Boundary and Initial Conditions .5 Model Simulation and Verification .5 Nitrogen Release Model in Water (Multi-diffusion Model) .2 Initial and Boundary Conditions for “Constant Release” Stage .3 Initial and Boundary Conditions for “Decay Release” Stage.4 Mesh Convergence Analysis .5 Model Verification and Comparison with Other Literature .6 Nitrogen Release Model in Soil Environment with Variation Coating Thickness .2 Urea Diffusion Coefficient in Soil Environment .3 Implementing Coating Thickness Distribution to the Model .4 Model Simulation and Validation .5 Effect of Coating Thickness Distribution on Nutrient Release .6 Effect of Soil Types on Nutrient Release .7 Applied Modeling to Predict Coating Material Parameters and to Design CRF Matching with Plant Growth .1 Modelling Scheme to Predict Coating Parameters Based on Multi- diffusion Model.2 Modeling Scheme to Design CRFs’ Geometry Matching with Nitrogen Uptake of Rice Plant .8 Characterization and Experimental set-up for model Verification .1 Materials and Apparatus used for Characterization and Experimental Verification .2 Characterization of Commercial Controlled-Release Fertilizers .1 Characterization of CRFs Distribution Using in the Release Test .2 Characterization of Coating Thickness Distribution .3 Urea Calibration Curve and Limit of Urea Detection .1 Urea Calibration Curve .2 Limit of Detection LOD and LOQ .4 Nitrogen Release Experiment .5 Water Penetration into the Coating. 97 CHAPTER 4 RESULTS AND DISCUSSION.2 Water Penetration in the Coating Layer .1 Model Verification through the Water Penetration of Agrium Fertilizer .2 Dynamic of Water Penetration into the Coating .3 Model of Nitrogen Release from Coated Granule in Water Environment (Multi-diffusion Model) .1 Model Verification through the Release of Nitrogen from Agrium® Coated Urea .2 Comparison with Experimental Data from Other Studies .4 Study the Release Behavior of Coated Urea Granule in Water Based on Multi-diffusion model .5 Model of Nitrogen Release from Coated Granule in Soil with Variation Coating Thickness (Porous Model).1 Model Verification in the Cases of Water and Soil Environment .2 Comparison between the Release of Nitrogen in Water and in Soil Environment .3 Effect of Coating Thickness Distribution on Nitrogen Release .4 Effect of Soil Types on the Release of Nitrogen .6 Applied Modeling to Predict Coating Material Parameters and to Design CRF to Match with Plant Growth.1 Predict Coating Parameters Based on Multi-diffusion Model .2 Modeling Base to Design CRF geometrical parameters to Match with Nitrogen Uptake of Rice Plant .1 Contribution of the Work .2 Recommendations for the Future Work.