This paper reports on the influence of independent variables in the ethylene glycol/soda pulping of olive wood trimmings (165-1958C, 30-90 min, ethylene glycol concentration 5-15%, soda concentration 2.5-7.5% and liquid/solid ratio 4-6), on the yield and Kappa index of the pulps and the strength properties (breaking length, burst index and tear index) of paper sheets. By using a central composite factorial design, equations that relate each dependent variable to the different independent

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... es were obtained which reproduced the experimental results for the dependent variables with errors less than 12%. Using a temperature of 1848C, ethylene glycol and soda concentrations of 15% and 7%, respectively, a liquid/solid ratio of 5:1 and a cooking time of 30 min results in yield, Kappa index, breaking length, burst index and tear index values that depart by 14.3%, 8.2%, 17.1%, 17.0% and 2.3%, respectively, from their optimum levels. These conditions result in substantial savings in power consumption and immobilised capital investments as they involve a lower temperature, a lower liquid/solid ratio, and a shorter time than the maximum values tested.