發(fā)布時間：2018-06-05 21:20

  本文選題：有機酸 + 清潔生產(chǎn)��； 參考：《中國科學(xué)院研究生院(過程工程研究所)》2015年博士論文

【摘要】：有機酸的傳統(tǒng)鈣鹽法生產(chǎn)伴生大量酸性硫酸鈣固體廢棄物,給環(huán)境帶來較大壓力,但鈣堿對有機酸發(fā)酵菌體友好,是某些有機酸濃度積累不可缺少的物質(zhì),鈣鹽沉淀步驟有利于提升有機酸產(chǎn)品的純度。本論文針對傳統(tǒng)鈣鹽發(fā)酵生產(chǎn)有機酸過程中產(chǎn)生大量固體廢棄物的共性問題,研究采用有機酸鈣鹽與可溶性碳酸鹽進行沉淀置換反應(yīng),擬解決有機酸生產(chǎn)過程產(chǎn)生硫酸鈣固體廢棄物、實現(xiàn)清潔生產(chǎn)。以乳酸和檸檬酸為研究對象,重點研究沉淀置換、離子交換、酸堿再生等步驟的問題和解決方法,在此基礎(chǔ)上構(gòu)建具有一定普適性的有機酸清潔生產(chǎn)新工藝。首先研究乳酸鈣和檸檬酸鈣與碳酸銨進行沉淀置換反應(yīng)的可行性,考察了反應(yīng)條件對沉淀置換反應(yīng)及碳酸鈣顆粒粒度的影響。結(jié)果表明,碳酸銨的加入量是乳酸鈣發(fā)酵液中鈣的物質(zhì)的量的1.06倍為佳,鈣離子去除率可達99%以上,乳酸鈣與碳酸銨之間的沉淀置換反應(yīng)可在15 min內(nèi)完成。碳酸銨與檸檬酸鈣中鈣的比值為1：1時,檸檬酸回收率達95%以上,檸檬酸鈣與碳酸銨之間的沉淀置換反應(yīng)所需的時間較長,本實驗條件下所需的反應(yīng)時間在2.5 h以上。沉淀置換反應(yīng)得到的懸濁液可采用自然沉降、再用板框過濾的方式進行固液分離。考察了離子交換法提取乳酸鈣沉淀置換上清液中的乳酸的工藝條件。乳酸鈣沉淀置換上清液的pH較高,使D319樹脂對乳酸的吸附量變小,殘留的碳酸根可被吸附到樹脂上,隨后用鹽酸洗脫時產(chǎn)生二氧化碳氣體,造成離子交換過程無法穩(wěn)定運行。提出的解決方法為：用乳酸調(diào)節(jié)沉淀置換上清液的pH值至7.0以下,然后采用加熱減壓法和離子交換法可有效去除殘留碳酸根。根據(jù)檸檬酸鈣沉淀置換上清液的特性,選擇“鹽-堿”兩室雙極膜膜堆結(jié)構(gòu)進行酸堿再生,考察了殘留鈣離子對酸堿再生的影響、鈣的存在形態(tài)及其去除方法。檸檬酸鈣沉淀置換上清液中的殘留鈣濃度有8.0 g/L以上,酸堿再生過程中可在鹽室產(chǎn)生檸檬酸鈣鹽固體。選擇草酸沉淀去除殘留鈣離子,鈣去除率約為60%。草酸沉淀法除鈣后的沉淀置換上清液的酸堿再生過程中,鹽室液仍會產(chǎn)生草酸鈣,沉積于隔網(wǎng)和離子交換膜表面。發(fā)現(xiàn)鹽室液開始出現(xiàn)渾濁與草酸鈣固體在膜堆內(nèi)沉積之間有一定的時間差,由此建立了間歇式堆外沉淀法去除殘留鈣離子的方法,可有效避免草酸鈣鹽在膜堆內(nèi)沉積,銨離子跨膜遷移的平均電流效率、膜通量和能耗分別達到95%、12.5 mol/(m2·h)和60 kWh/kmol,與檸檬酸銨水溶液的酸堿再生參數(shù)相當�？疾炝顺恋碇脫Q劑制備與沉淀置換反應(yīng)兩步驟的耦合,表明耦合可降低體系中的產(chǎn)物(碳酸銨)濃度,從而增大碳酸銨的表觀生成速率�？疾炝巳樗嵘a(chǎn)工藝中的酸堿再生步驟與離子交換的洗脫步驟的耦合,表明耦合可有效降低酸室液中游離H+和C1-濃度,緩解了酸室中H+滲漏的程度,使Cl-的跨膜遷移通量提高了3.5%,平均電流效率提高了56.25%,能耗降低了29.61%�？疾炝颂妓徕}(沉淀置換步驟得到的碳酸鈣)循環(huán)利用的效果,表明使用循環(huán)碳酸鈣進行乳酸發(fā)酵可大幅提高乳酸發(fā)酵水平,乳酸濃度增加了32.41%,產(chǎn)酸速率提高了33.17%,菌體濃度提高了19.34%；循環(huán)碳酸鈣的比表面積大,具有較好的pH維持能力,顆粒內(nèi)含有少量氮元素,且乳酸桿菌可在顆粒上形成洞狀結(jié)構(gòu),為其自身提供較好的微環(huán)境,有效提高了乳酸發(fā)酵水平。在實驗室規(guī)模下,對乳酸和檸檬酸的清潔生產(chǎn)工藝進行串聯(lián),結(jié)果表明,乳酸總收率可達90%以上：乳酸清潔生產(chǎn)新工藝的估算成本約為6782.5元,與傳統(tǒng)鈣鹽法生產(chǎn)乳酸的成本相當；乳酸清潔生產(chǎn)工藝得到的精制乳酸符合某聚乳酸生產(chǎn)企業(yè)的原料采購要求。草酸脫鈣后的檸檬酸沉淀置換上清液經(jīng)酸堿再生得到的鹽室終點液,經(jīng)陽離子交換樹脂除雜、常規(guī)減壓濃縮、結(jié)晶得到檸檬酸固體,其中未檢出草酸、銨離子和鈣離子。
[Abstract]:The traditional calcium salt method of organic acid produces a large amount of acid calcium sulfate solid waste, which brings great pressure to the environment, but calcium alkali is friendly to organic acid fermentation bacteria. It is an indispensable substance for the accumulation of some organic acid concentration. The calcium salt precipitation step is beneficial to the promotion of the purity of organic acid products. This paper is aimed at the production of organic acid by traditional calcium salt. In the process of acid, a large number of common problems of solid waste are produced. The study uses organic acid calcium salt and soluble carbonate for precipitation replacement reaction. It is intended to solve the production process of organic acid to produce calcium sulphate solid waste and realize clean production. On this basis, a new process of clean production of organic acids with certain universality was constructed. The feasibility of precipitation replacement reaction of calcium lactate and calcium citrate with ammonium carbonate was first studied, and the effects of reaction conditions on the precipitation replacement reaction and the particle size of calcium carbonate were investigated. The results showed that the addition of ammonium carbonate was added. The amount is 1.06 times the amount of calcium in the calcium lactate fermentation liquid, the removal rate of calcium ion is above 99%, the precipitation replacement reaction between calcium lactate and ammonium carbonate can be completed within 15 min. The recovery rate of citric acid is over 95% and the precipitation replacement reaction between calcium citrate and ammonium carbonate is more than 95% when the ratio of calcium carbonate to calcium citrate is 1:1 The time required for this experiment is more than 2.5 h. Natural sedimentation can be used in the precipitation replacement reaction. The process conditions for the extraction of lactate in the supernatant from calcium lactate precipitation and replacement of supernatant by ion exchange method are investigated. The pH is higher, which makes the adsorption and quantitative change of lactic acid by D319 resin small, the residual carbonate can be adsorbed on the resin, and then the carbon dioxide gas is produced by hydrochloric acid elution, which causes the ion exchange process to not run steadily. The solution is to adjust the pH value to less than 7 with lactic acid in the precipitation replacement, and then use the heating and decompression method. And ion exchange method can effectively remove residual carbonate. According to the characteristics of calcium citrate precipitation replacement supernatant, "salt alkali" two chamber bipolar membrane reactor structure is selected for acid base regeneration, and the effect of residual calcium ion on acid base regeneration, the existence form of calcium and the removal method of calcium in the supernatant of calcium citrate precipitation replacement supernatant are investigated. Calcium citrate solid can be produced in the salt chamber during the process of acid base regeneration. The concentration of calcium citrate can be removed by oxalic acid precipitation. Calcium removal rate is about 60%. oxalic acid precipitation process. Calcium oxalate can be produced in the process of precipitation replacement supernatant. Salt chamber liquid will still produce calcium oxalate, deposited on the surface of septum and ion exchange membrane. There is a certain time difference between the turbidity and the deposition of calcium oxalate in the membrane reactor. Thus the method of removing residual calcium ions by intermittent heap precipitation method is established, which can effectively avoid the deposition of calcium oxalate in the membrane reactor, the average current efficiency of the transmembrane migration of ammonium ions, the flux and energy consumption of the membrane are 95%, 12.5 mol/ (M2 h), respectively. And 60 kWh/kmol, which is equivalent to the acid base regeneration parameters of ammonium citrate solution. The coupling of the preparation of precipitate replacement agent and the two step of the precipitation replacement reaction is investigated. It shows that the coupling can reduce the concentration of the product (ammonium carbonate) in the system, thus increasing the apparent formation rate of ammonium carbonate. The acid base regeneration steps and ions in the lactic acid production process are investigated. The coupling of the elution steps of the exchange shows that the coupling can effectively reduce the concentration of free H+ and C1- in the acid chamber, alleviate the degree of H+ leakage in the acid chamber, increase the transmembrane migration flux of Cl- by 3.5%, increase the average current efficiency by 56.25%, and reduce the energy consumption by 29.61%. to investigate the efficiency of calcium carbonate (calcium carbonate from the precipitate replacement step). The results showed that the lactic acid fermentation could greatly improve the lactic acid fermentation level, the lactic acid concentration increased by 32.41%, the acid producing rate increased by 33.17%, the body concentration increased by 19.34%, the specific surface area of the circulating calcium carbonate was large, the pH maintenance ability was better, the particles contained a small amount of nitrogen elements, and the Lactobacillus could form on the particles. In the laboratory scale, the total yield of lactic acid and citric acid can be over 90%: the estimated cost of the new lactic acid cleaner production process is about 6782.5 yuan, and the lactic acid is produced with the traditional calcium salt method. The refined lactic acid obtained from the lactic acid cleaner production process meets the purchasing requirements of the raw material of a polylactic acid production enterprise. The citric acid precipitation replacement supernatant after the calcium oxalic acid decalcification is obtained by acid base regenerated salt chamber end solution, and the citric acid solid is obtained by the cation exchange resin removal, the conventional decompression condensation, and the crystallization of the citric acid. Acids, ammonium ions and calcium ions.
【學(xué)位授予單位】：中國科學(xué)院研究生院(過程工程研究所)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TQ921

【參考文獻】

相關(guān)期刊論文 前10條

1 高艷榮;王建友;盧會霞;;雙極膜電滲析清潔制備NaOH和H_2SO_4的試驗研究[J];水處理技術(shù);2013年10期

2 張才華;王昆;李衛(wèi)星;范益群;邢衛(wèi)紅;;雙極膜電滲析提取乳酸的影響因素[J];南京工業(yè)大學(xué)學(xué)報(自然科學(xué)版);2012年05期

3 王倩;叢威;;雙極膜電滲析再生酸堿過程中的陰膜漏氫研究[J];過程工程學(xué)報;2011年03期

4 楊冰;許穎;季君暉;張維;王萍麗;王小威;趙劍;;琥珀酸發(fā)酵過程中的產(chǎn)物抑制特征及樹脂吸附原位分離的研究[J];食品與發(fā)酵工業(yè);2011年04期

5 秦鋒;王淑娟;Hallvard F.Svendsen;陳昌和;;碳化氨水中含碳量的分析及測量[J];清華大學(xué)學(xué)報(自然科學(xué)版);2011年04期

6 姜紹通;張巧蘭;吳學(xué)鳳;羅水忠;潘麗軍;;不同中和劑對米根霉發(fā)酵產(chǎn)L-乳酸的影響[J];食品科學(xué);2010年23期

7 高年發(fā);楊楓;;我國檸檬酸發(fā)酵工業(yè)的創(chuàng)新與發(fā)展[J];中國釀造;2010年07期

8 李秀芬;陶麗佳;李溯;陳堅;;萃取條件對支撐液膜法提取有機酸的影響[J];環(huán)境科學(xué)與技術(shù);2009年09期

9 王軍;劉素俠;歐陽平凱;;聚丁二酸丁二醇酯的研究進展[J];化工新型材料;2007年10期

10 徐國謙;儲炬;王永紅;莊英萍;張嗣良;彭華瓊;邱伙琴;;不同的中和劑對L(+)-乳酸發(fā)酵的影響[J];工業(yè)微生物;2007年04期

相關(guān)碩士學(xué)位論文 前1條

1 張妮;雙極膜電滲析清潔生產(chǎn)有機酸的研究[D];合肥工業(yè)大學(xué);2008年

，

本文編號：1983437