Arnaud Chapuis

Cirad - La recherche agronomique pour le développement | CIRAD

In a number of tropical countries, the expansion of cassava processing is tied to the development of small-scale, energy-efficient pneumatic dryers used to dry flour and starch. To facilitate this development, in this study a model of the pneumatic drying of starch particles was developed, to be fitted to measurements taken from large cassava proce...

Cassava (Manihot esculenta) is the most important staple food in sub-Saharan Africa. However, the shelf-life of the crop is short and, for this reason, the roots are usually processed into more stable products like cassava flour by village-based enterprises. Most of these enterprises use small-scale locally built pneumatic dryers, but such dryers s...

In sub‐ S aharan A frica, cassava is grown by smallholder farmers and is the principal source of calories for the local population. However, the short shelf life of cassava associated with poor infrastructure in the region results in significant postharvest losses. The expansion of small‐scale cassava processing could reduce these losses, but the a...

The development of biofuel production in Burkina Faso, raises high expectations regarding the development of rural energy access and the substitution of imported fossil fuels. Several initiatives for biofuel production from Jatropha oilseeds were launched in recent year by NGOs and private operators. The government is planning to define a policy fr...

The performance of oil expression from Jatropha curcas L. (Jatropha) seeds using a pilot scale continuous screw press was studied. The influence of seed pre-treatment, i.e. whole, crushed and deshelled seeds, screw-press operational settings (shaft rotational speed and press cake outlet section) was investigated. For each experiment, the material f...

Dewatering is a critical step in cassava flours processing. Compression dewatering kinetics are useful to understand and design a dewatering operation. The dataset presents dewatering kinetics measured in a filtration–consolidation cell at constant pressure between 4 and 21 bar, on several cassava mashes (three batches fragmented at two particle si...

Dehydration is a critical step in many food processes. In this paper, we propose an original strategy, based on experiments and modelling, to evaluate the performance of the compression dewatering of cassava and to help design dewatering equipment. The dewatering of various grated cassava roots was experimentally studied through 42 experiments in a...

BACKGROUND The isosteric heat of desorption is vital in evaluating the energy performance of food dryers. The isosteric heat of desorption was investigated for different cassava (Manihot esculenta Crantz) products prepared as flour or starch, with and without fermentation. An automated moisture sorption gravimetric analyser was used to measure the...

A pneumatic drying model, developed in a previous work, was tested and validated based on a series of 56 experiments of cassava starch drying conducted on a pilot-scale pneumatic dryer. After fitting two parameters, the average diameter of starch particles and a heat loss factor, the model predicted the effects of main operating conditions with a l...

The objective of this study was to define, from literature data, the most relevant water sorption isotherm to use in simulation models for cassava root processing. The isotherm should be as global and generic as possible. Compiling isotherms from the literature showed that the variety of cassava and the level of processing generally have a negligib...

This chapter describes the development and scaling-out of flash dryer innovations for more efficient production of high-quality cassava flour (HQCF) and starch at small-scale. The diagnoses of cassava-processing SMEs revealed their energy expenditures for drying were considerably higher than large-scale industrial companies, which was mostly due to...

Scaling of innovations is a key requirement for addressing societal challenges in sectors such as agriculture. Research for development (R4D) programs, projects and other interventions struggle to make innovations go to scale. Current conceptualizations of scaling are often too simplistic and narrow, and more systemic and multidimensional perspecti...

This study was designed and carried out to ascertain the situation and perceptions of end users of cassava flash drying equipment in Nigeria with the aim of giving suggestions to policies and approaches for improved technology. Forty-one processing firms were selected and interviewed. Descriptive analyses were used and a logistic regression model w...

Scaling of innovations is a key requirement for addressing societal challenges in sectors such as agriculture, but research for development programs struggles to make innovations go to scale . There is a gap between new complexity-aware scientific theories and perspectives on innovation and practical approaches that can improve strategic and operat...

Small-size enterprises drying cassava in Africa mostly use fixed-bed dryers or pneumatic dryers. The objective of this study was to determine which of those two dryers is the best choice for this operation. Energy performance, product quality and costs were measured and analysed using a comparative experiment design. Each dryer was considered as a...

Ministère des Mines eLes biocarburants, notamment l’huile végétale carburant à base de graines de Jatropha représentent une alternative à l’utilisation de carburants d’origine fossile. L’enjeu principal de la substitution des carburants fossiles par les biocarburants demeure le prix de vente du carburant qui est très fortement dépendant du prix de...

In Burkina Faso, biofuels represent a great opportunity to address important economic development issues such as modern energy access and dependence on energy imports. Jatropha Curcas (Jatropha) has been identified as the most suitable feedstock for biofuel industry development. Considering the socio-economic issues and the commitment of the govern...

The planning of energy supply systems for buildings in urban areas is a key-element in the reduction of energy consumption and greenhouse-gases (GHG) emissions. However, it also represents an increasingly complex task notably due to the emergence of new energy conversion technologies. The use of a framework based on a diagram representation of ener...

This study concentrates on determining how to implement the legal framework at different institutional levels in an integrated approach for the planning and management of energy systems in urban areas. There are mainly five levels of decision able to influence the performances of urban zone in a Swiss city, namely the international, national, canto...