Online Measurement of Oxygen-Dependent Enzyme Reaction Kinetics.

As the application of biocatalysis to complement conventional chemical and catalytic approaches continues to expand, an increasing number of reactions involve poorly water-soluble substrates. At required industrial concentrations necessary for industrial implementation, this frequently leads to heterogeneous reaction mixtures composed of multiple phases. Such systems are challenging to sample, and therefore, it is problematic to measure representative component concentrations.

Development of in situ product removal strategies in biocatalysis applying scaled-down unit operations.

An experimental platform based on scaled-down unit operations combined in a plug-and-play manner enables easy and highly flexible testing of advanced biocatalytic process options such as in situ product removal (ISPR) process strategies. In such a platform, it is possible to compartmentalize different process steps while operating it as a combined system, giving the possibility to test and characterize the performance of novel process concepts and biocatalysts with minimal influence of inhibitory products. Here the capabilities of performing process development by applying scaled-down unit operations are highlighted through a case study investigating the asymmetric synthesis of 1-methyl-3-phenylpropylamine (MPPA) using ω-transaminase, an enzyme in the sub-family of amino transferases (ATAs).

Scale-up of industrial biodiesel production to 40 m(3) using a liquid lipase formulation.

In this work, we demonstrate the scale-up from an 80 L fed-batch scale to 40 m(3) along with the design of a 4 m(3) continuous process for enzymatic biodiesel production catalyzed by NS-40116 (a liquid formulation of a modified Thermomyces lanuginosus lipase). Based on the analysis of actual pilot plant data for the transesterification of used cooking oil and brown grease, we propose a method applying first order integral analysis to fed-batch data based on either the bound glycerol or free fatty acid content in the oil. This method greatly simplifies the modeling process and gives an indication of the effect of mixing at the various scales (80 L to 40 m(3) ) along with the prediction of the residence time needed to reach a desired conversion in a CSTR.

Enzymatic pretreatment of low-grade oils for biodiesel production.

The alkaline process for making biodiesel (fatty acid methyl esters, or FAME) is highly efficient at the transesterification of glycerides. However, its performance is poor when it comes to using oil that contain significant amounts of free fatty acids (FFA). The traditional approach to such feedstocks is to employ acid catalysis, which is slow and requires a large excess of methanol, or to evaporate FFA and convert that in a separate process.

Real-time model based process monitoring of enzymatic biodiesel production.

In this contribution we extend our modelling work on the enzymatic production of biodiesel where we demonstrate the application of a Continuous-Discrete Extended Kalman Filter (a state estimator). The state estimator is used to correct for mismatch between the process data and the process model for Fed-batch production of biodiesel. For the three process runs investigated, using a single tuning parameter, qx  = 2 × 10(-2) which represents the uncertainty in the process model, it was possible over the entire course of the reaction to reduce the overall mean and standard deviation of the error between the model and the process data for all of the five measured components (triglycerides, diglycerides, monoglycerides, fatty acid methyl esters, and free fatty acid).

Mechanistic modeling of biodiesel production using a liquid lipase formulation.

In this article, a kinetic model for the enzymatic transesterification of rapeseed oil with methanol using Callera™ Trans L (a liquid formulation of a modified Thermomyces lanuginosus lipase) was developed from first principles. We base the model formulation on a Ping-Pong Bi-Bi mechanism. Methanol inhibition, along with the interfacial and bulk concentrations of the enzyme was also modeled.

Identification of critical parameters in liquid enzyme-catalyzed biodiesel production.

Callera™ Trans L, a liquid formulation of Thermomyces lanuginosus lipase, has recently shown great promise as a cost-efficient catalyst for methanolysis of triglyceride substrates, specifically in the BioFAME process. However, identifying the right combination of temperature and concentrations of catalyst, water and methanol to realize the full potential of the reaction system has remained a challenge. This study presents an investigation of the impact of temperature, enzyme and water concentration on the reaction, as well as the effect of methanol feed rate for the conversion of rapeseed oil in a fed-batch reaction system.

A two-stage enzymatic ethanol-based biodiesel production in a packed bed reactor.

A two-stage enzymatic process for producing fatty acid ethyl ester (FAEE) in a packed bed reactor is reported. The process uses an experimental immobilized lipase (NS 88001) and Novozym 435 to catalyze transesterification (first stage) and esterification (second stage), respectively. Both stages were conducted in a simulated series of reactors by repeatedly passing the reaction mixture through a single reactor, with separation of the by-product glycerol and water between passes in the first and second stages, respectively.

Chemo-enzymatic epoxidation-process options for improving biocatalytic productivity.

The reactor choice is crucial when designing a process where inactivation of the biocatalyst is a problem. The main bottleneck for the chemo-enzymatic epoxidation has been found to be enzyme inactivation by the hydrogen peroxide, H(2) O(2) , substrate. In the work reported here, the effect of reaction parameters on the reaction performance have been investigated and used to establish suitable operating strategies to minimize the inactivation of the enzyme, using rapeseed methyl ester (RME) as a substrate in a solvent-free system.

Biocatalytic polyester acrylation--process optimization and enzyme stability.

An OH-functional polyester has been acrylated via transesterification of ethyl acrylate, catalyzed by Candida antarctica lipase B (CalB) in two different preparations: Novozym 435 and immobilized on Accurel MP1000. The batch process resulted in incomplete acrylation as well as severe degradation of the polyester. A high degree of acrylation was achieved by optimization through the application of low pressure (15 kPa), continuous inflow of ethyl acrylate and continuous distillation to evaporate the by-product, ethanol.

Efficient enzymatic acrylation through transesterification at controlled water activity.

Enzymatic acrylation is a process of potentially strong interest to the chemical industry. Direct esterification involving acrylic acid is unfortunately rather slow, with inhibition phenomena appearing at high acid concentrations. In the present study the acrylation of 1-octanol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was shown to be as much as an order of magnitude faster when ethyl acrylate served as the donor of the acrylic group.

Effects of acid concentration and solvent choice on enzymatic acrylation by Candida antarctica lipase B.

Lipase-mediated acrylation is an attractive alternative to more traditional chemical processes, since it provides specific catalysis under mild conditions. A detailed study of the effects of solvent choice and substrate concentrations on the acrylation of octanol by Candida antarctica lipase B (Novozym 435) is presented. Acrylic acid was found to have a pronounced inhibitory effect.