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Towards a benign and viable rhodium catalyzed hydroformylation of higher olefins: Economic and environmental impact analyses, solvent effects and membrane-based catalyst separation.

機(jī)譯：尋求良性和可行的銠催化的高級烯烴加氫甲酰化：經(jīng)濟(jì)和環(huán)境影響分析，溶劑影響和基于膜的催化劑分離。

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Researchers at the Center for Environmentally Beneficial Catalysis (CEBC) had previously reported a novel rhodium-based hydroformylation process concept based on the use of CO2-expanded liquids (CXLs) to intensify rates and obtain higher linear/branched aldehydes selectivity at relatively mild temperatures (30-60°C) and pressures (∼4 MPa). This dissertation continues investigations aimed at addressing the fundamental and practical issues associated with this concept.;ReactIR studies of Rh/triphenylphosphine-catalyzed 1-octene hydroformylation, complemented by microkinetic and reactor modeling investigations revealed that the intrinsic kinetic rate constants are of similar magnitude with or without CO2 addition to the reaction mixture. This implies that the enhanced reaction rate observed in CXL is due to the increased hydrogen solubility in that medium.;Environmental impact analysis revealed that the overall toxicity index for the CEBC process is approximately 40 times less than the Exxon process against which the CEBC process was benchmarked. Economic analysis of the CXL concept revealed that at an aldehyde production rate of 19,900 kg/(kg Rh·h), > 99.8% rhodium has to be recovered per pass for the CEBC process to be competitive with the Exxon process. Assuming a similar hydroformylation turnover frequency, rhodium recovery levels that exceed this criterion for economic viability were successfully demonstrated in a membrane-based nano/ultra-filtration reactor system using polymer supported phosphorus ligands, synthesized and provided by researchers from the Department of Chemistry. During continuous filtration of a toluene-based solution containing polymer-supported Rh complexes, the Rh and P concentrations in the permeate, quantified using ICP analysis, were on the order of a few tens of ppb. During continuous 1-octene hydroformylation studies in the membrane reactor at a syngas pressure of 0.6 MPa and 60°C, the 1-octene conversion and product (mostly aldehydes) concentrations reached a steady state with the Rh concentrations in the permeate stream being lower than 120 ppb. However, the conversions and product concentrations during the continuous run are lower than those obtained in a batch ReactIR under identical operating conditions. This is attributed to syngas starvation in the membrane reactor that might be caused by inadequate mixing.;In complementary investigations, it was found that the dissolution of CO2 in the organic phase (to create CO2-expanded liquids) decreases the viscosities of the mixtures with increasing CO2 pressure. This offers an opportunity to enhance mixing and also tune the membrane flux so as to increase the throughput of the membrane filter. The demonstrated technology concept, when fully optimized, should find applications in a variety of other applications in homogeneous catalysis, including hydrogenation and carbonylation of conventional and biomass-based substrates.
機(jī)譯：有益于環(huán)境的催化中心（CEBC）的研究人員先前已經(jīng)報道了一種新穎的基于銠的加氫甲?；に嚫拍?，該概念基于使用CO2膨脹液體（CXL）來提高速率并在相對溫和的溫度下獲得更高的線性/支鏈醛選擇性（ 30-60°C）和壓力（?4 MPa）。本論文繼續(xù)著眼于解決與該概念相關(guān)的基本和實(shí)際問題的研究。; Rh /三苯基膦催化的1-辛烯加氫甲?；腞eactIR研究，以及微動力學(xué)和反應(yīng)器模型研究表明，內(nèi)在動力學(xué)速率常數(shù)與或不向反應(yīng)混合物中添加二氧化碳。這表明在CXL中觀察到的反應(yīng)速率提高是由于該介質(zhì)中氫溶解度的增加所致。環(huán)境影響分析表明，CEBC工藝的總體毒性指數(shù)比CEBC工藝所針對的?？松梨诠に嚨图s40倍。標(biāo)桿。對CXL概念的經(jīng)濟(jì)分析表明，在醛生產(chǎn)速率為19,900 kg /（kg Rh·h）的情況下，CEBC工藝要與?？松梨诠に嚫偁帲勘楸仨毣厥沾笥?9.8％的銠。假設(shè)類似的加氫甲?；苻D(zhuǎn)頻率，銠的回收水平超過了經(jīng)濟(jì)可行性這一標(biāo)準(zhǔn)，這是在基于膜的納米/超濾反應(yīng)器系統(tǒng)中成功證明的，該系統(tǒng)使用了聚合物支持的磷配體，由化學(xué)系的研究人員合成和提供。在連續(xù)過濾包含聚合物負(fù)載的Rh絡(luò)合物的甲苯基溶液期間，使用ICP分析定量的滲透液中Rh和P濃度約為幾十ppb。在膜反應(yīng)器中在0.6 MPa和60°C的合成氣壓力下進(jìn)行連續(xù)的1-辛烯加氫甲酰化研究期間，1-辛烯的轉(zhuǎn)化率和產(chǎn)物（主要是醛）的濃度達(dá)到穩(wěn)態(tài)，而滲透物流中的Rh濃度低于120 ppb。但是，在相同的操作條件下，連續(xù)運(yùn)行期間的轉(zhuǎn)化率和產(chǎn)物濃度低于在批處理ReactIR中獲得的轉(zhuǎn)化率和產(chǎn)物濃度。這歸因于膜反應(yīng)器中合成氣的不足，這可能是由于混合不充分引起的。在補(bǔ)充研究中，發(fā)現(xiàn)CO2在有機(jī)相中的溶解（生成CO2膨脹的液體）會降低混合物的粘度。增加二氧化碳壓力。這提供了增強(qiáng)混合并調(diào)節(jié)膜通量的機(jī)會，從而增加了膜過濾器的產(chǎn)量。充分優(yōu)化后，已證明的技術(shù)概念將在均相催化中的各種其他應(yīng)用中找到應(yīng)用，包括常規(guī)和基于生物質(zhì)的底物的氫化和羰基化。

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